Magazine R

different from the other epistemological corroborated and extended by further Features entities mentioned above, in that work. So, even with Wallace or some one can fully understand evolution unknown taking Darwin’s place, it without ever having read a single line of is safe to say that by now we would Back to Darwin’s own writings. This is because have an idea how the different kinds what Darwin laid out as a theory has of organisms diversified. On the other This year’s 200th birthday of Charles become superseded by the empirical hand, what Darwin did is in a sense Darwin and 150th anniversary of the confirmation and theoretical expansion not so different from what, say, Kant publication of his book On the Origin of of the concept of evolution — in did, in that he erected a theoretical Species is a welcome occasion to take a particular its mathematical formulation framework aimed at explaining the moment and reflect on what Darwin, that and its unification with genetics. world and created concepts that were father figure of biology, and particularly So, if we can understand evolution at the time largely abstract, such as his works mean today — aside from all perfectly well without having to read natural selection. After all, in Darwin’s the due veneration and the obligatory Darwin, what would have happened if time, biology was far away from being lip-service. Is the value of Darwin’s Darwin hadn’t been born? Of course, the empirical, experimental science book today only that of a historical we would not have The Origin. But it is today and was in its reliance on document, the initial formulation of a observation, description and reasoning, fundamental, revolutionary idea? Most much more like philosophy or history would of course agree that the idea of — which is why it used to be referred evolution, which since has influenced to as ‘natural philosophy’ or ‘natural human culture beyond the realm of pure history’. science, is what really matters. But what So, what about today’s actual about the book itself? relevance of Darwin’s book itself, The very fact that one is tempted to in practical terms? Though it still ask such a question perhaps reflects is common practice to directly or the fundamentally different role the indirectly refer to Darwin’s writings in individual plays in science as opposed the scientific literature, is there actual to, for instance, the arts and humanities. value in treating them, in particular The A simple way of highlighting this Origin, as if it they were philosophical difference is to speculate how the world works that ought to be read in the would be different if a given scientist or original? Is it worthwhile, today, 150 artist had not been born. It can be safely years past its publication, to go back said that we would not have ‘Tristan and to The Origin and read it? And, does Isolde’, ‘Don Quixote’, or the ‘Critique of anyone actually still read it? With these Pure Reason’ had Wagner, Cervantes or questions in mind, we started asking Kant never lived. At the same time, we scientists from different areas of biology would surely know the laws of gravity, — from molecular biology to ecology — the planet Uranus or the structure of to read or re-read The Origin for Current DNA, had Newton, Herschel or Watson Biology and share their thoughts, much and Crick never lived. In the case of as one would do in a book club. artistic or philosophical works, then, The responses, which are printed the role of the individual is that of a in the following pages, are excitingly creator rather than that of a discoverer, (12.2.1809 – 19.4.1882). With diverse: some had already read the which makes artistic or philosophical permission from John van Wyhe ed., The book many times while others had never achievements so much more contingent Complete Work of Charles Darwin Online touched it before. While of course no on the person of the achiever. (http://darwin-online.org.uk). biologist can but be in awe about the This fundamental difference is fundamental importance of Darwin’s reflected in the way information is given the fortunate historical situation, idea for biology, the perspectives on transmitted. When a student of biology it can be comfortably argued that Alfred his book 150 years down the line range learns today about DNA structure, Russell Wallace would have stepped in from literal excitement to the feeling she will most likely read a chapter in and, as it were, filled that ‘empty niche’. that, as a text, The Origin itself may a textbook that simply summarises To what extent he would have done so, well be dated by now. However, the the known facts. She can understand however, and how ‘Wallaceism’ would thoughts that (re-)reading The Origin the structure of the DNA double helix have been different may be a point stimulated in the members of our virtual without ever having read Watson and of debate over a drink at this year’s book club show that — despite the fact Crick’s papers, in fact without even many celebrations; after all, Wallace, that evolutionary fact and theory can be knowing who they are. The same is not surpassed by Darwin, never bothered to grasped without having to read Darwin’s true for the humanities: a student of formulate his theory in full. original works — The Origin as a book is Kantian philosophy will be expected to This uncertainty perhaps betrays still very powerful and very much alive. read Kant’s original works, a student of the notion that The Origin is somewhat And what better way of commemorating Marxism will have to read Marx. of a hybrid; on the one hand, seen in the anniversary of the man and his book Speaking of -isms, what about retrospect, it has characteristics of than by revealing its enduring vitality? ‘’ in that context? At face a scientific discovery in that it builds value, Darwinian evolution is no on empirical data and becomes Florian Maderspacher Magazine R

punctuated patterns in the fossil record punctuated equilibrium, molecular Feature could be caused by rapid evolution drive, the idea of symbiosis as an in small peripheral populations that evolutionary force, evo-devo, and the rapidly supplant their ancestors. The notion that evolution is driven by the (Re)Reading The ‘Kluge-Kerfoot hypothesis’, published self-organization of molecules. Some in 1973, proposes that the traits most of these ideas are worthwhile, others Origin variable within populations are those simply silly; but none do more than add most likely to differ markedly between a room or two to the Darwinian manse. Charles Darwin’s 1859 book On the populations. This idea, now the Often declared dead, Darwinism still Origin of Species is much referenced, foundation for sequence-based tests refuses to lie down. So by all means especially in this double anniversary of natural selection on genes, appears let’s retain the term. It is less of a year. But, does anyone still read it? in chapter five ofThe Origin. Darwin jawbreaker than ’modern evolutionary And if so, what is the book itself like even suggests that family selection biology’, and has not, as was feared, as a text? We have asked biologists might explain the evolution of sterile misled people into thinking that our from a range of fields— evolutionary insect castes. field has remained static since1 859. biologists, but also geneticists, No popular work of science — and What better honorific than ’Darwinism‘ ecologists, paleontologists and we must remember that this book to fête the greatest biologist in history? molecular biologists — to re-read (or was written mainly for the public, not read) The Origin for Current Biology. Darwin’s colleagues — ever had such Jerry A. Coyne is an evolutionary geneticist Below are the responses, contributed a dramatic impact on both scientific in the Department of Ecology and Evolution by: Andrew Berry, Matthew Cobb, opinion and human consciousness. at the University of Chicago. He works on Simon Conway-Morris, Jerry Coyne, Buttressed by innumerable facts the origin of species, using Drosophila as Hopi Hoekstra, Peter Lawrence, Robert gleaned personally or through tireless a model organism, and is the author of the forthcoming book ‘Why Evolution is True’. May, Christiane Nüsslein-Volhard, Mark correspondence, Darwin works his Ptashne, Matt Ridley and Marlene Zuk magic with a subtle but irresistible style of argument. He asks rhetorical Robert May questions, disputes with himself, Jerry Coyne raises and answers every objection On being invited to re-read Darwin’s to his own theories, and in the end Origin of Species and comment on it, Many of my colleagues say that so convinced his readers that they my first question was which edition. we should quietly shelve the term not only bought his ideas, but in the As Darwin sought to mollify critics, ‘Darwinism’. We don’t, they argue, process jettisoned three thousand successive editions lengthened, call classical physics ‘Newtonism’, years of religious explanation for life until the sixth and final edition is nor relativity ‘Einsteinism’. So why and its apparent design. twice the length of the first. Some of saddle our field with an eponymous And from the outset Darwin got it these changes are adumbration of personality cult, especially when we’ve mostly right. Evolution occurred, all examples to strengthen an argument, learned so much since The Origin of species have common ancestors, others are circumlocutions to avoid Species appeared in1859? Why not call and the main (but not the only) engine problems (for example, given that it ‘modern evolutionary biology’, or the of evolutionary change is natural the nuclear forces which fuel the insidious-sounding ‘neo-Darwinism’? selection. These ideas have endured sun were unknown to the physics The best answer to this revisionism is unchanged, becoming scientific truths. of Darwin’s day, Kelvin and others to reread The Origin itself. In no other Over the past century and a half, much observed that the geological time field has the work of a single individual of our time has been spent sweeping available for evolutionary processes created a research program that has up after the Darwinian elephant, was at most a few million years; this is endured for a century and a half. (It analyzing the droppings from The why, in successive editions, numerical is inconceivable, for example, that a Origin. True, Darwin wasn’t always estimates of the sweep of evolutionary modern paper on electromagnetism correct: He got genetics wrong, and time disappeared into a verbal fudge). would begin with the words “Ever his views on species and speciation So I re-read the first edition. A since Faraday...”) Besides Darwin’s are pretty wonky. And of course century and a half has passed, but ’Big Five‘ ideas: evolution, natural evolutionary theory has advanced: the language remains fresh, and the selection, common ancestry, lineage Systematics, continental drift, and ideas compelling. As John Bonner splitting (speciation), and gradualism, population genetics are all areas and I wrote in introducing a reprinting The Origin broaches ideas only now untouched by his looming shadow. of The Descent of Man in 1981, “It is coming to fruition — ideas often tossed Still, these advances amount to the genius of Darwin that his ideas, out in one brief sentence. refinements of Darwinism rather than clothed as they are in unhurried We read, for instance, about how its Kuhnian overthrow. Evolutionary Victorian prose, are almost as modern evolution can be constrained by biology hasn’t suffered the equivalent now as they were when they were first pleiotropy, “the many unknown laws of of quantum mechanics. But some published”. And never before or since correlation of growth”. We encounter biologists, chafing in their Darwinian has a book so changed our view of the the idea that some traits might not straitjacket, periodically announce world, and of our place in it. be subject to any form of selection, new worldviews that, they claim, will This being acknowledged, I doubt and that these neutral traits could overturn our view of evolution, or at that the Origin is commonly read today remain as polymorphic “fluctuating least force its drastic revision. During as an inspiration for research. But it elements”. There is the suggestion that my career, I have heard this said about is heavily cited: a recent analysis of Current Biology Vol 19 No 3 R

Even in their own day, there was something of cricket’s distinction (which persisted for a further century) between Gentlemen and Players in their relationship. It should, however, be acknowledged that Victorians often referred to the Darwin–Wallace idea of evolution by natural selection. All of which emphasises the disparity between the high profile Darwin bicentennial celebrations and associated academic industry, and the relative neglect of Wallace. In the interests of equal time, I am now off to re-read Wallace.

Robert, Lord May of Oxford, OM AC FRS, is a physicist-turned-ecologist and Professor in the Zoology Department at Oxford University. He was Chief Scientific Adviser to the UK Government (1995-2000) and President of the Royal Society (2000-2005).

Matt Ridley

I deliberately picked up a late edition of The Origin of Species, the sixth edition, published in 1872, interested to see how Charles Darwin, an obsessive reviser of his own prose, had coped with all the comments the book had received in the 13 years since it had first come out. For instance, in this edition, Darwin enthusiastically adopts ’s coinage `survival of the fittest’. The book certainly reads in places like a conversation with his critics, as in this sardonic passage: “My judgment may not be trustworthy, but after reading with care Mr Mivart’s book, and comparing each section with what I have said on the same head, I never before felt so strongly convinced of the general truth of the conclusions here arrived at.” Biology is the science of exceptions to rules, and what is so striking about The Origin of Species is that Darwin builds his argument for a single great rule by finding hundreds of curious anecdotes, experiments, oddities and surprises in the cornucopia of nature, Original Origin: Frontispiece of the first edition 1859. Reproduced with permission from John each one seemingly exceptional yet all van Wyhe ed., The Complete Work of Charles Darwin Online (http://darwin-online.org.uk). pulling towards a general conclusion. The power of the book comes not books in ecology and evolution puts basic researchers. Ultimately, however, from its relentless logic so much as its it a close second to Fisher’s Genetical the Origin provides a telling illustration enormous reservoir of examples large Theory of Natural Selection, and of the inadequacy of measuring true and small. There is no topic on which well ahead of most contemporary impact by counting citations. he cannot find a race of pigeon or a monographs (Elworthy (2007). Bull. Interestingly, Wallace’s books — species of barnacle, or story from a Brit. Ecol. Soc. 38, 55-57). I suspect, including that which gave us the naturalist somewhere in the world, to however, that this may owe more to classification of biogeographical illustrate his point. Lots of them would the Darwin industry among historians realms which we still use — do not not pass muster today, being, to put and philosophers of science than to feature in Elworthy’s catalogue. it mildly, not from the peer-reviewed Magazine R literature: ”I may add, that according to Peter Lawrence literature, but banned from scientific Mr. Pierce, there are two varieties of the usage. I don’t know why, but dulling wolf inhabiting the Catskill Mountains, “The greatest scientific advance of down our scientific writing is not in our in the United States, one with a light the last 1000 years was providing the best interest. By contrast, in Darwin’s greyhound-like form, which pursues evidence to prove that human beings time, Victorian fashion encouraged deer, and other more bulky with shorter are independent agents whose lives a flowery style as well as intellectual legs, which more frequently attacks the on earth are neither conferred nor freedom; he took full advantage of shepherd’s flock.” controlled by celestial forces…… both. He could write explorative and When Darwin goes wrong, it is nothing was more important than educative prose. He could spend many nearly always because he relies on the providing the means to release men pages explaining narrow but important wrong ideas of others — on received and women from the hegemony of the distinctions between different wisdom that turned out to be incorrect. supernatural.” (Mellman, I. and Warren, viewpoints and, time and again, There are three striking examples: G. (2000). The road taken: past and one can see the outcome of careful First, heredity; with splendid, waffling future foundations of membrane traffic. reading and deep reflection. Our data- obscurity, Darwin attributes variability Cell 100, 99-112.) dominated publications, pared down to ”changed conditions of life”, to In this vital mission to discredit the to fit them into limited space, would “correlated growth” and to the ”use or supernatural, nothing has proved more be much more comprehensible if there disuse of parts”. He even concedes the important than The Origin of Species. were more argument, more explanation grossest of Lamarckian fallacies: ”The Here is just one nice argument from and more justification indeed, if we evidence that accidental mutilations hundreds: “He who admits the doctrine reflected more I think we could make can be inherited is at present not of the creation of each separate big reductions in our published pages decisive; but the remarkable cases species, will have to admit that a by making sure they carry and convey observed by Brown-Sequard in sufficient number of the best adapted at least one message of note. guinea-pigs, of the inherited effects of plants and animals were not created Although Darwin’s book is primarily operations, should make us cautious in for oceanic islands; for man has about arguments and evidence, he denying this tendency.” unintentionally stocked them far more does not forget the power of a simple Second, the age of the earth; Darwin fully and perfectly than did nature”. experiment. Just one example: He accepts the calculation of Sir William argues that the worldwide dispersal Thompson (later Lord Kelvin) that the of some freshwater plants is due to earth is about 200 million years old, “The power of the book comes migrating birds carrying mud on their but confesses uneasily that ”it can feet; so he takes three tablespoons hardly be considered as sufficient for not from its relentless logic so of mud from a local pond and, over the development of the varied forms much as its enormous res- 6 months, found he could grow 537 of life.” Thompson was out by a factor ervoir of examples large and plants from it. Darwin has whole of seven, because he had omitted the chapters discussing the points of view effect of radioactivity which is slowing small.” of others, dismissing contrary opinions the cooling of the earth. (Matt Ridley) with persuasive arguments. He took Third, continental drift; Darwin time to communicate extensively struggles to explain why different with other specialists. By contrast, in continents have different faunas on I had only dipped into this wonderful modern scientific discourse, we see them, and why the geological record book in my student days. But what the deadening hand of a new etiquette is so intermittent in most places. He a revelation for a somewhat jaded fuelled by careerist calculations. thinks that land bobs up and down in scientist to read it now! It is not only We now have little open debate, the same place: ”the great oceans are the brilliance, farsighted and original different views are avoided rather still mainly areas of subsidence, the nature of the ideas, there is the sheer than confronted, controversial papers great archipelagoes are still areas of diversity of knowledge, the pervading are not quoted and their publication oscillations of level, and the continents presence of thought, of simple direct is resisted. But of course Darwin not areas of elevation.” experiments, of debate, of argument, only had something important to say The Origin of Species is a fossilized the consideration of other views he also did not have to keep in with scientific argument. That is to say, it and the style. In writing and reading opinion-formers in order to get grants! is a moment of intellectual awakening scientific articles nowadays, we Peter A Lawrence has studied the genetics of frozen in its own time. It was superbly become imprisoned, constrained in adapted to its Victorian environment, animal design using insects for 45 years. He is what is considered appropriate and currently working in the Zoology Department struggled successfully for existence, our vocabulary is reduced. Also our of the University of Cambridge and the MRC proved fit enough to survive and gave sentences are stifled by fashion and Laboratory of Molecular Biology, Cambridge, rise to still fitter living descendants, by journals that kill invention and UK. which survived many attempts to drown independence with their strict word them in new-fangled fallacy, having limits and their ’house style‘. Just one shed along the way their worst features. example: punctuation. Darwin used Matthew Cobb everything, even the long dash and Even the most ardent evolutionist Matt Ridley is the author of, among other the explanation mark. In my scientific books,‘The Red Queen’, ‘Genome’ and the writing I have been frequently told that regularly shakes his or her head in biography of Francis Crick. He lives near these are not allowed — OK for great wonder at an amazing adaptation Newcastle upon Tyne, UK. and asks: How on earth did that Current Biology Vol 19 No 3 R

and not only because it was hard make the most economic use of the to imagine how, say, bees might precious wax, thereby encouraging have evolved the ability to make the appearance of hexagonal cells. hexagonal cells. He recognised that But the most important part of the existence of widespread sterility this chapter centres on what Darwin in social insects — dealt with in some called the ”special difficulty” of detail in this chapter — presented sterility in social insects: ”With him with ”one special difficulty, which the working ant we have an insect at first appeared to me insuperable, differing greatly from its parents, yet and actually fatal to the whole theory absolutely sterile; so that it could [of natural selection]”. His resolution never have transmitted successively of this fundamental problem not only acquired modifications of structure or showed his genius, it also prefigured instinct to its progeny. It may well be some of the most important asked how is it possible to reconcile developments in evolutionary theory this case with the theory of natural over a century later. selection?” Darwin starts his chapter on Darwin’s explanation of the instinct by linking behavioural and selection of sterile individuals is that morphological adaptations: ”No ”selection may be applied to the complex instinct can possibly be family, as well as to the individual, produced through natural selection, and may thus gain the desired end.” except by the slow and gradual In other words, if individuals that are accumulation of numerous slight, related to the sterile ants reproduce, Fact: at New York’s LaGuardia aiport. Photo- yet profitable, variations’, he writes, and somehow share the character in graph kindly provided by Alex Gann. emphasising that these variations question, then natural selection can are ‘produced by the same unknown lead to the evolution of sterility. causes which produce slight Although Darwin was referring to evolve? Darwin was no different, deviations of bodily structure”. ‘family selection’, and used examples as shown by what may seem to be In the pages that follow, he from cattle breeding and horticulture one of the stodgier chapters of The emphasises the existence of to back up his insight, there is a Origin of Species — Chapter eight variation for various ‘instincts’, direct link between this explanation on ‘instinct’. This chapter deals and puts forward an explanation and what was probably the greatest with the evolution of behaviour, of how they might have evolved. development in evolutionary thinking and focuses on the astonishing In the case of pointing in hunting in the last 50 years — Bill Hamilton’s behaviour of social insects, in dogs, he points out it is merely ”the work on kin selection, ‘inclusive particular, honeybees and their exaggerated pause of an animal fitness’ and the evolution of altruism. intricate honeycombs. As Darwin preparing to spring on its prey”, However, the most important writes: “He must be a dull man who while the evolution of cell-making contribution of this part of Darwin’s can examine the exquisite structure in honeybees can be understood in book is its unstated implication that of a comb, so beautifully adapted terms of a series of the existence of the human mind is on a continuum to its end, without enthusiastic discrete behavioural elements. Some with those of animals. Just as his admiration.” of these putative stages can be seen study of morphological evolution Darwin was not the first person to in various bee species — the wax showed us that we are nothing think about the evolution of behaviour cells produced by bees vary from the special — just a particularly smart — his grandfather, , cylinders produced by bumble bees and talkative bipedal ape — his as well as the Frenchmen Jean- to the elaborate hexagons made by work on ‘instinct’ implies that human Baptiste Lamarck and Pierre-Jean honeybees. mental life can be understood Cabanis, had all tackled the subject Darwin also describes a series of as the product of evolution and, at the end of the 18th century. experiments he carried out which above all, that consciousness is a But Charles Darwin’s approach showed that the thickness of the physical phenomenon. Darwin not was doubly different to those of cell wall was a decisive factor in only gave us the means to interpret his predecessors. He interpreted indicating to the honeybees when the whole of the natural world, he behaviour as a product of evolution to stop work. By adding coloured also provided us with the tools by natural selection, thereby obliging wax, he showed that several bees needed to investigate one of the himself to explain behavioural will act together on making cells, greatest scientific and philosophical adaptations in terms of other, less with one individual moving from one conundrums: Where our thoughts developed characters. And, as shown cell to another before it is finished, come from. by virtually every page of the Origin, indicating that bees, like other he was incredibly rigorous, seeking to animal architects described in the Matthew Cobb is a Senior Lecturer in address all possible objections to his chapter, do not have an internal Animal Behaviour at the University of Manchester. He is the author of ‘The Egg theory, grinding down criticisms one ‘image’ of what they are building. & Sperm Race: The Seventeenth Century by one. Darwin then argued that natural Scientists who Unravelled the Secrets of Sex, The material in Chapter eight was selection would have given an Life and Growth (published in the USA as particularly important to Darwin, advantage to those bees that could ‘Generation’). Magazine R

Christiane Nüsslein-Volhard and Darwin had a much more direct Embryonic as well as larval traits approach and closer contact to nature had been most important in defining “When we no longer look at an organic than is possible nowadays. Of course, larger groups in the natural system. being as a savage looks at a ship...” he was singularly fortunate, because Darwin explains this pattern by the use — the first thing that struck me when the long voyage on the Beagle allowed and disuse of organs: As there is no re-reading The Origin: Darwin’s book him as a naïve observer — unprejudiced selection acting on embryonic forms is wonderful literature — exiting, and with a mind wide open — to collect that are not yet functional, embryos interesting, very well written, in an and learn about a richness of facts that or larvae will reveal the ‘prototype’ almost colloquial style. Darwin goes to is exceptional. However, it would be of a given group, while the adults are great lengths not to be too tedious and entirely wrong to say that his theory often highly specialised and adapted seems to be constantly worried about depended solely on the opportunities to their lifestyle. The barnacles Darwin loosing the reader. To anyone interested given to him by the voyage. studied, for example, can be recognised in biology, the book can never appear as crustaceans only by virtue of their dull: there are so many facts and larval form. Likewise, he explains the observations about natural history, “I had only dipped into this existence of rudimentary organs that the diversity of animals and plants would have no reason to exist were it a — after all, this is the topic of the book wonderful book in my student creator’s world. Although this evidence — but also about agriculture, domestic days. But what a revelation for for his theory is often overlooked, and crops or the breeding of pigeons, and a somewhat jaded scientist to developmental biology until recently spreading out into behaviour, geology, played little if any role in post-Darwinian fossils, embryology. All of these read it now!” (Peter evolutionary theories, the mere fact observations are placed in the context Lawrence) that a natural classification is possible of the “one large argument” of descent at all is most compelling, and one with modification. There is hardly wonders why others before Darwin any field that is left out — except for, In the final chapter ofThe Origin, have not interpreted common traits perhaps, chemistry and physiology. which impresses me most, the by assuming common ancestors. Darwin did not know about argumentation is based largely on well It is striking that the famous single microorganisms, and therefore his book known work of other naturalists, as illustration of the book is used to deals little with pathogen resistance well as his own thorough investigations explain this argument, underlining the or health, a topic which nowadays is of barnacles. The chapter deals with importance Darwin himself attributed recognized as most important for the classification: “From the first dawn to it. In this illustration, Darwin fills in evolution of organisms. In retrospect, of life, all organic beings are found to the missing intermediates by designing Darwin’s biggest limitation — as many resemble each other in descending a hypothetical pedigree to explain have pointed out — was that he did degrees, so that they can be classed the natural system: if all the species not understand genetics; this worried in groups under groups”. People that had ever existed, would come to him a great deal, and he tried hard to have ordered plants and animals long life again, the missing intermediates delineate “laws of variation”, but he before, most notably according to — together with all those that died out could not explain the origin of variation. Linnaeus’ systema naturae (1735), a in side branches — would also appear He emphasizes, however, that sexual ‘natural’ system, which takes affinities — allowing an undisputable natural reproduction increases variation and or relationships between organisms into classification, based on common fitness, and acknowledges the “strong account as opposed to an ‘artificial’ descent with modification. principle of inheritance”. Reading classification based on, say, size, When settled at Downe, having the these chapters, it sometimes feels colour, habitats or type of food. It had advantage of living on the family purse, as if Darwin got close to Mendel’s been realised that different traits are without the need for grant writing, job laws, but all was buried in a big mess of different value for classification, finding and scientific administration, of often contradictory reports about and that similarities could also arise Darwin could follow up his thoughts all sorts of crosses among wild and in parallel: the different value of and obsessions with utmost freedom, domesticated species. Perhaps, in the homologous (similar by common type) interrupted only by his family and case of inheritance, the abundance of as opposed to analogous (similar by illness. We owe his great book also observations and cases that make The common function) structures was to a loving wife, his kids, pigeons Origin so entertaining to read, clouded clearly appreciated. Darwin emphasises and plants, and a walk around the Darwin’s view and made it impossible that his theory of descent with sandwalk everyday. I don’t envy him for for him to see the clear rules that modification has the power to explain the illness or for his fame, but for his Mendel recognized through his elegant the natural system, and he mentions the independence and for the peace of the experimental system. intuition of the biologists before him: place which provided the setting for The Origin is also a testimony of “Community of descent is the hidden the development of the great theory of Darwin’s obsession — a brilliant idea, bond naturalists where unconsciously evolution. conceived rather early and his fear he seeking” in their classifications. Christiane Nüsslein-Volhard is a director at might be hanged for it, as well as an The fact that in embryos the more urge to be understood, to find support. the Max Planck-Institute for Developmental general features that characterise a type Biology in Tübingen Germany, where A book like this could probably not be develop earlier than the specialised she studies the genetic basis of embryo written by a present day scientist: for ones had also been observed before, development in fish and flies. She won with one, much of the diversity of nature in particular by Karl Ernst von Baer. Ed Lewis and Eric Wieschaus the 1995 Nobel has disappeared in the meantime, Prize in Physiology or Medicine. Current Biology Vol 19 No 3 R

implied prediction: “the absence of distinctive breeds of cat […] may be attributed to selection not having been brought into play”. I suspect that Rocky, my Abyssinian, would reject the idea that humans have since moulded his type rather than the other way around. Darwin jolts us into confronting an inspiring fact: the world is not transparent. Every interesting scientific construct is a product of the imagination. I was recently assured that the lambda switch — the molecular mechanism controlling lysogeny versus lysis of the lambda bacteriophage — was there for the taking, i.e. an easily understood set of interactions that required more looking than thinking. Thank heaven (sic) that is not true, for how dull our tasks would have been (and continue to be). The good Bishop, stumbling across the lambda switch in its current guise, would surely remark on the impossibility of evolving this intricate, seemingly irreducibly complex machine. We would have him over a barrel: we can explain how a set of simple binding reactions, each additional binding reaction making the machine work a bit more efficiently, went into making the switch the marvellous thing it appears to be. Darwin of course knew nothing about lambda — in fact, The Origin, Origin of The Origin: First Pencil Sketch 1842. in its first edition, considers only Reproduced with permission from John van Wyhe ed., The Complete Work of Charles Darwin ‘recent’ evolution, that which resulted in the diversification of plants and animals. In hindsight ‘The Origin’ Mark Ptashne were irrelevant or wrong, but which illustrates a principle of scientific he couldn’t answer. analysis: if you want to uncover In the last chapter of the first edition I say ’encountering‘ The Origin, universal mechanisms, concentrate of The Origin of Species Darwin rather than ‘re-encountering’, on the simplest examples; because, famously says “...this whole volume because my previous attempts paradoxical as it might seem at first, is one long argument…”, and urges to read the book failed. Who has Darwin was analyzing the ‘simplest’ the reader to weigh all the pros the patience to dig through the examples of evolution. Unlike what and cons. Sly fellow, as though all convoluted sentences, extracting the happened during the evolution scientific positions, ‘proofs’, are not buried nuggets? Other writings of of bacteria, essentially no new arguments that aim to convince the Darwin are delightful, and maybe this enzymatic activities appear in the reader. What is so unusual about dangerous book was written so as, elaboration of plants and animals. The Origin, and what makes it so once again, to deflect confrontation. In fact, we are made up of a number thrilling is the abstraction involved In any event my Kindle came to the of genes embarrassingly close to here. We are urged to accept the rescue — there I found a ‘condensed’ those found in a fly, and the fly genes idea that species arose by natural version of The Origin in which each encode proteins very similar to those selection in the face of an incoherent sentence has been pared down by found in us. picture of how variation arises the elimination of unnecessary words. The trick natural selection and is transmitted, and the then- And in this version the book comes exploited, so as to use common unimpeachable testimony of the to life. Had I stuck to the original I enzymes to produce disparate physicists that the earth cannot be as might have gotten the ‘big picture’, organs and organisms, was to vary old as required. Darwin rarely left his but I would have skimmed the details, the regulation of these common house, motivated, I would guess, by the astounding array of observations enzymes. Many of these enzymes his dread of facing attacks he knew brought to bear. Here’s one with an have a wide array of possible Magazine R substrates, and what changes found these changes may be hard to more objective purpose of piling during evolution are the specificities interpret. Surely that is a big part of up the evidence. Darwin knew his imposed by binding reactions. The the problem in analyzing the multi- enemy intimately, but was far too Blind Plumber will work on any pipe factorial contributions to human astute to engage in a head-on clash. in your house — you have to lead, or variation and disease. Darwin never Darwin was right, and he knew ‘recruit’, him to the one or more pipes said it would be easy. Indeed his it. His expressions of doubt are that should be worked on. Similarly, vision predicts it can’t be. largely rhetorical and how seamless the enzyme RNA polymerase will — at least from a distance — is the transcribe into RNA essentially any Mark Ptashne is Ludwig Professor of edifice upon which he constructs gene to which it is recruited. This Molecular Biology at Sloan Kettering his theory. Yet, it is equally intriguing Institute in New York, where he studies trick applies to every aspect of the mechanisms of gene regulation. He has how he conceals his intellect: regulated production of proteins and authored two books (‘A Genetic Switch’ the carefully marshalled facts are other macromolecules — including (Third Edition) and ‘Genes and Signals’, allowed to speak for themselves transcription of genes, splicing, with Alex Gann) and occasionally writes for and the implications introduced with transport and translation of mRNA, Current Biology about biological regulation restraint and circumspection— a proteolysis of proteins, transduction and related topics. sotto voce naturalist. Darwin never of extracellular signals , and so on. doubted his abilities. The Origin, Over recent evolutionary time scales however, offers precious few clues it is the recruiters and their sites “...my previous attempts to as to the roots of his intellectual on targets — genes, proteins, RNA read the book failed. Who has adventure. Cambridge, where his — that changed, not the enzymes scientific mind actually crystallized, themselves. And that, it would seem, the patience to dig through the goes unmentioned. In the opening is an easy task for natural selection. It convoluted sentences, extract- line of the Origin, Darwin hints at the is not surprising that we understand ing the buried nuggets?” Beagle being the catalyst, but what less well how the earlier stages a contrast this book is to what we evolved. (Mark Ptashne) usually refer to as ’The Voyage’. In A regulatory world that uses this earlier work plenty of questions binding reactions to impose are posed, but very few answered. specificity inevitably looks messy, True the Malthusian formula is you might say unnecessarily invoked, but the sense of enquiry is Simon Conway Morris ‘complex’. To get these rather crude far more one of muddle. The seeds reactions to work properly requires were sown, but germination was a add-on after add-on, usually in the A small confession: No!, no! Not that slow process and in many ways the form of more binding reactions that one! I confess, yes, this is the first Origin is a late flower. Yet it reveals inhibit one or the other step, that time I have read The Origin cover to glimpses of an intense acuity of result in destruction of a protein when cover. And could it be that like with vision. Combine this with an enviable it exceeds a certain concentration, another well-known sphere of human gift of lateral thinking, and if the dark that inhibit another crucial binding engagement a little experience, brain of Darwin is not exposed, it is reaction, and so on. These ever- dare I say maturity, helps? A book at least visible. Such is also clear tinkered with systems work, but at of genius? Of course! But what because even though the Origin is a price: just as the regulatory world suddenly became clear is that this a deep book, its surface sparkles can be assembled stepwise, so is is a book haunted by the ghost of with prescient insights. Of course, it rather easily disassembled, with William Paley — the grand-father of a priori readings from our vantage each subtraction making the situation creationist thinking and exponent point can make too much of half- worse. Glance through a modern of seemingly irrefutable arguments articulated thoughts, but in this cancer textbook and you will see a for organic design. The Origin is mind of a genius we see a catalogue kind of ‘evolution in reverse’ — the Darwin’s riposte. Its metaphorical of potentialities. These include accumulation of mutations that take power depends on suspense and a hypotheses that we now identify the cell back to a more ‘primitive’ scattering of clues, but significantly with r-selection, group selection, state,one devoid of the usual Paley himself is mentioned only the red queen, incumbency, controls. Almost without exception, once. And cleverly not in the context biogeographical barriers, character every mutation involves, directly or of his ideas on organic design but states, stratigraphic hiatuses and indirectly, a binding reaction, or the in an oblique dig at the question of embryological recapitulation. So, too creation or destruction of a binding natural evil. First and foremost, The — in a way that still seems to puzzle site by an enzyme. Origin is an exorcism of the doctrine half the biologists I know — Darwin The good news — Darwin would of special creation, and conducted succinctly explains how ancestors have loved it — is that it is easy to by one of the most skilled exorcists are themselves not the direct see in principle how changes in just science has ever seen. The brief intermediates, and, as we know now, a few surface residues of a protein crescendo in the last chapter is may bear precious little resemblance can, by affecting binding reactions, preceded by repeated and sudden to their distant progeny. But even contribute to recent evolutionary flashes of disdain, a quick insertion when his genius fails him there is still change. The bad news is that of the knife before the narrative a whiff of future discoveries. one cannot predict where these calmly continues in its ostensibly changes will be found, and once Current Biology Vol 19 No 3 R

of nature when he came to any sort of metaphysics, again like some of his most fervent supporters today, he was hopelessly out of his depth. But at least he knew some of his limits. It is no accident that even as he supposed absolutely correctly that famously “Light will be thrown on the origin of man and his history” he suspected that mind and the origin of life might forever fall outside his theory. And as in so many other ways Darwin might just be right.

Simon Conway Morris is Professor of Evolutionary Palaeobiology in the Earth Sciences Department at Cambridge, and is working on his next book, ‘Darwin’s Compass’.

Marlene Zuk

Although the students in our graduate program in evolutionary biology take a Back to the roots: Darwin’s sandwalk and ‘thinking path’ near Downe House in Kent. Photo- core course in evolutionary theory for graph from wikipedia.org. which The Origin of Species is required reading, one could certainly describe But there is something obsessive reality? I don’t think so. Again, the book as a work that everyone cites, about Darwin. Just as he piled up the ghost of Paley and his siren but few people have actually read. So the evidence, so his whole view of voice of organic design must be is Darwin’s masterpiece still valuable evolution was ultimately relentless, expelled. Only later, with the Origin 150 years later? Or is our requirement an unceasing, almost manic entrenched, did Darwin reveal his just a form of intellectual hazing, conviction that no piece of evidence deep knowledge of contrivance, making the newcomers suffer as a was too trivial, too unimportant. as in the form of climbing plants. rite of passage? I am always struck Where time is effectively endless, And if the Origin is an exorcism by Darwin’s ability to use details of the scrutiny of selection unsleeping against Paley, so obliquely Darwin natural history without being transfixed and untiring, the most trivial arrives with a mouthful of nails to by them or viewing them as an end advantage seized upon so the Origin finally hammer shut the coffin of in themselves. Amidst the carefully becomes effectively the calculus of Lamarckism. Why else the strenuous compiled notes from Mr. Chauncey biology, where fathomless aeons of and repeated insistence that the Wright or the Rev. W.B. Clarke, one geological time witness evolution physical environment can effectively never loses sight of why Darwin is creeping along gradualistic paths. play no role in his theory? After mentioning an example. The antennae No wonder his eliding of variety all, if biological form should be so of the Hymenoptera, for example, with species and agonizing of the moulded then might not organisms “as Westwood has remarked, are nature of hybrids and the question of simply be responding to the ebb and most constant in structure; in another sterility is so central to his argument flow of inanimate forces? division they differ much, and the of continuum and why, so rightly, he Darwin knew he stood on a Darien differences are of quite subordinate was deeply puzzled by what we now peak with almost unlimited vistas, value in classification; yet no one will refer to as the Cambrian ’explosion‘. but seemingly unaware that he was say that the antennae in these two Yet for all of that, the Origin also staring into an abyss. Integral divisions of the same order are of has some strange lacuna. to his scheme were metaphors of unequal physiological importance.” Despite Darwin’s enthusiasm for struggle, the weak and dominant, (Chapter 14) The actual nature of the perfection of form and the victory and extinction, battle and hymenopteran antennae is of little integration of the organism, the yielding, invasion and retreat: “let interest to me, but it is abundantly book contains remarkably little on the strongest live and the weakest clear that we are reading about them functional biology. He knew some die”, but all to the greater good as in in such detail because Darwin was medicine, was a skilled dissector, panglossian mode he also wrote “no wrestling with the question of how we and it is all the odder because fear is felt, that death is generally choose characters for classification of — even if he lived in tranquil prompt, and that the vigorous, the organisms, which remains an important Down House — England hummed healthy and the happy survive and question to this day. Few modern with the sound of machines and multiply”. Like many others after him biologists can both appreciate natural technological innovation. Is it a Darwin muffed the profound problem history and recognize that it is not an gentleman’s aversion to a sordid of natural evil. Despite his generosity end in itself. Magazine R

As a behavioral ecologist, I it for the first time. As part of our mid- frequently and so unexpectedly. But, appreciate Darwin’s grappling with level course on evolution at Harvard, curiously, our students seldom have behaviour as a trait, and his trying we assign The Origin (alongside a such a balanced response: they either to understand, in chapter eight, selection of recent/classic papers and love it or hate it. Our statistical analysis whether behaviour is subject to textbook readings) to be read chapter of this data hasn’t gone beyond mere natural selection in the same manner by chapter throughout the semester. eyeballing, but there seems to be no as morphology. Behavior presented This exercise is mildly controversial; major disciplinary effect: life-science Darwin with one of his greatest colleagues have criticized us, saying majors are as likely to love (or hate) challenges, altruism, and it is clear that that we should focus on current The Origin as physicists or historians Darwin saw the study of behaviour as science rather than revisiting the past. or engineers. Here are a few quotations a legitimate avenue for evolutionary Our response is twofold: uniquely from a recent set of anonymous biology. In contrast, modern scientists among the sciences, evolutionary evaluations: spend far too much time splitting biology is dominated by the one disciplinary hairs, distinguishing authority, the one book. If Steve Gould “Textbook unnecessary. Darwin’s ecology from evolution from behaviour, hadn’t entitled his first collection of ‘Origin of Species’ a great reason to and often disparaging whatever essays ‘Ever Since Darwin’, we would take course. Journal articles useless”. subfield with which they do not identify. still be starting our papers with these “The Origin = Very Painful” The title of the book is misleading, very words. Second, the continued “I enjoyed reading Darwin’s Origin. It at least in its usual usage as simply relevance and freshness of The Origin seemed appropriate to read the primary The Origin of Species without the is especially remarkable when you source, even if not every idea has found continuation by Means of Natural consider what Darwin didn’t know. still to be correct”. Selection or The Preservation of “The reading of Darwin was Favoured Races in the Struggle for pathetically useless. It did nothing Life. How species begin and how one to add to the course and just made group splits up into two is only a small “The Origin is an exorcism of discussion groups worthless as well”. part of the focus of the book, and even the doctrine of special crea- “Origin — Awesome! So cool to the subtitle doesn’t do it justice. The tion, and conducted by one of read!” book is about how, when, and why “It’s OK when he’s not talking about organisms can change through time, a the most skilled exorcists” plants and pollen, like that time with breathtaking scope that is nonetheless (Simon Conway Morris) the slave-making ants (that was pretty thoroughly plumbed. The Descent of cool).” Man is similarly unfortunately titled “Origin is awful (sorry). Way too long and therefore also perhaps not read and redundant.” as much as it should be, and although Natural selection is an explicitly “Reading the last chapter of The its subtitle, And Selection in Relation genetic theory, and yet Darwin had no Origin over the last week was magical.” to Sex, is more descriptive of the viable theory of transmission genetics; “Reading Darwin is a nice contents, it too is not particularly biogeographic arguments play an requirement, but I don’t think it should compelling. The Descent of Man is important role for Darwin and yet be tested on the exam.” about sexual differences writ large, in he had no knowledge of continental humans as well as other organisms, drift; and speciation, arguably the We would, of course, like to another blockbuster. Who knows – if lynchpin of the evolutionary process, transform the “Origin = Very Painful” Darwin had better titles, maybe he was terra incognita for Darwin. crowd into the “Origin — Awesome” would have been even more influential. That Darwin’s “one long argument” one, but we suspect that this will Although it’s hard to imagine how he remains compelling and coherent remain a case of not being able to could have sexed up his last work, The today is testimony to his unwillingness please all the people all of the time. Formation of Vegetable Mould through — except on rare occasion, such as in Regardless, we are confident that, the Action of Worms with Observations the case of bears evolving into whales ten years on — as they go about on their Habits. — to go beyond the data before him. their work in hospitals, at biotech For example, as an acute observer, companies, and perhaps occasionally Marlene Zuk is a Professor of Biology at he was familiar with the extent of at universities — even the students the University of California, Riverside. Her phenotypic, and therefore genetic, who were not enamoured with The research interests center on behavioural ecology and sexual selection, and she variation in natural populations, Origin when they took our course will is particularly interested in the effects of and was content to treat genetics recall with pride that they read every parasites on host behaviour, ecology, and as a black box; only later, when his word of the book and grappled with evolution. hand was forced, did he produce even its more obscure and unquoted a specious model of genetics, passages. The details of what we pangenesis. The Origin is thus a book- taught them will be long gone, but Andrew Berry and Hopi Hoekstra length testament to the scientific The Origin and all of its lessons will method. remain. Instead of actually re-reading and We expected the students to respond commenting on Darwin’s Origin in the same way as we did when we first Andrew Berry is a Lecturer in Biology and ourselves, like the other contributors read it – to groan at the occasionally Hopi Hoekstra is a John L. Loeb Associate of this series, we report here on what lumbering Victorian prose, but to Professor of Biology and the Curator of our students had to say about reading appreciate the insights that crop up so Mammals. Both work at Harvard University.